The invention relates to a method of distributing liquid media, in particular extinguishing liquids like water or the like in the form of a mist or a large-droplet stream from a low-pressure supply line into spaces, in particular living or household rooms or the like to fight fire where the pressurized extinguishing liquid is made into individual streams and these streams are separately set in rotation and subsequently the streams are combined to form a spray cone.
The invention further relates to an apparatus for carrying out the above-described method with a support on which is provided a fitting for connection to a low-pressure supply line, a connection body, and a turbulence chamber surrounding the connection body, the turbulence chamber being traversed by separate streams of the extinguishing liquid.
Sprinkler for applying extinguishing liquids in stationary fire-extinguishing systems have been known for long. German 2,703,459 describes a sprinkler nozzle for upright, horizontal, and pendant mounting with a nozzle body and an impingement plate that is connected with the nozzle body with at least two support elements fixed to an edge of the impingement plate as well as an arrangement which blocks the nozzle opening of the sprinkler nozzle on manufacture and which is formed of a closure element sealing the nozzle opening and a release element pressing against the later but which can release its force on the closure element and allow the extinguishing-water stream to exit. The closure element is provided with an ejector which, when the retaining force is released, works with the force of the extinguishing water, the ejector being fixed to the joined parts of the sprinkler head when same is in standby condition.
German 2,924,654 describes a sprinkler for automatic fire-extinguishing systems, which is comprised of a housing defining a flow passage for the extinguishing liquid, a two-arm frame on the housing carrying a distributor cap, a cover cap closing the flow passage, and an assembly between the two caps which has a lever, a support strut with two laterally perforated tabs, and a temperature monitor set between the tabs. The support strut has a projecting antijam arm whose longitudinally bent main portion extends generally parallel to the struts and which on sprinkler activation engages against the frame and distributor cap.
Other solutions (EP 0,505,762, U.S. Pat. No. 3,834,463, or U.S. Pat. No. 5,505,383) serve mainly for applying a large-droplet spray of the extinguishing agent in nearly constant amounts over time, because on one hand the diameters of the outlet openings of the sprinklers is fixed and on the other hand the extinguishing-media pressure in the supply line is constant. This leads in a fire mainly to usage of a great deal of water by the stationary extinguishing system with all the inherent disadvantages of overdimensioning the pumps, pipes, and storage containers for extinguishing media in the system.
The sprinkler nozzle described in German 3,624,939 produces a spray stream that has small and large droplets, more particularly small drops in a relatively small edge area and large drops in a central area. This is done in that the outlet opening or the outlet openings are downstream of inlet openings whose flow cross section is somewhat smaller than the flow cross section of the outlet opening or openings.
A spray nozzle for producing a mist with low pressure, in particular to fight fire in stationary water-mist fire-extinguishing systems is known from EP 0,671,216. This known nozzle is built radially into a pipe of a fire-extinguishing system and is comprises of a housing holding a flow body that traversed by a conically tapering turbulence/mixing chamber. The surface of this turbulence/mixing chamber is formed with spiral grooves with axial inlets that communicate with inlet openings for the water. An annular space permits a further stream of water into the inner turbulence/mixing chamber. There is thus stream separation. The one path leads via the inlet openings and the twist passages to cylindrical nozzle openings and there produces and inner spray cone. The second path extends via the annular chamber and tangential bores to an annular gap from which the water exits as an outer spray cone.
The known solution serves mainly for applying a large-droplet inner spray stream and a fine-droplet outer spray stream. It is not possible to obtain an initial fine-drop spray mist when the fire starts and a large-droplet spray mist when the fire is under way to apply the extinguishing media. All of the above-cited disadvantages of the state of the art have nothing to do with this known solution.
Starting from this state of the art it is an object of the invention to provide a method and apparatus of the above-described type by means of which it is possible with nearly constant supply pressure of the extinguishing means to, with time, in accordance with the whether the fire has just started or is under way to apply a fine-droplet spray mist and a large-droplet spray mist so as to minimize water use, reduce water damages in fire, and to increase the efficiency of the fire-extinguishing system in any installation.
This object is attained by a method and an apparatus of the above-described type wherein the turbulence intensity and the ratio of small and large droplets in the spray are adjusted between zero and a maximal value by adjustment of the flow volume and the flow speed of streams of the extinguishing liquid either separately or synchronously and that the adjustment is controlled by a signal generator after a fire starts dynamically in accordance with the development of the fire.
The invention is characterized above all by its simplicity and is particularly applicable to wet systems. In contrast to the known state of the art a simple flow regulation in the separated and rejoined streams of the extinguishing fluid produces an excellent influencing of the turbulence intensity in dependency of whether the fire has just started or is underway. When the streams are produced it is further possible to impinge small and large surfaces of an object to be protected with spray cones and spray streams of different shape and composition. According to the above-given requirements as a fire starts up the apparatus according to the invention produces at first a mist like droplet stream. The signal generator can in this case be a smoke detector. As the fire develops a large-droplet spray stream is needed so a further detector, for instance a heat detector, produces a signal which acts on the adjuster of the apparatus in that the flow cross section of the opening of the slot is enlarged.
The solution according to the invention reduces water use to fight a fire substantially and simultaneously reduces water damage caused by the unregulated outflowing of the extinguishing medium. The fire-extinguishing systems can be better tailored to the dynamics of the fire as it starts and develops.